Burner



0. L. BOCK Dec. 22, 1936.

BURNER Filed Nov. 2, 1932 VII A I W I ]i2 u nZ'0r: Oscar L. B00 in,

Patented Dec. 22, 1936 UNITED STATES PATENT OFFICE BURNER Oscar L. Bock,Madison, Wis. Application November 2, 1932, Serial No. 640,845

3 Claims.

This invention relates in general to a device for burning hydrocarbon,and particularly to a burner using oil as a fuel.

One of the important objects of the invention is to provide a newandimproved burner embodying novel features and principles which areessential to the complete combustion of the fuel and the elimination ofthe carbon deposit or formation at the point of oil entrance into thechamber where the fuel is burned or consumed.

Another important object of the invention is the provision of a burnerhaving a hearth over which temperatures higher than the end point of thehydrocarbon can be held and maintained throughout the vaporizing area,and the distributing of air unifomny over the entire hearth so as tounite at relatively high temperatures with the fuel and thereby causecomplete combustion of the hydrocarbon.

A further object of the invention is the provision of a burner which hasmeans for introducing oil onto the hearth in such a manner that thepresence of the adjoining fuel feed pipe will not produce a cold sectionin the vaporizing area, and which is provided with means to controlcombustion so as to cause the flame to burn in suspension on the outertop lining of the burner.

A still further object of the invention is the method or process ofcombustion which consists in introducing a liquid hydrocarbon bygravity, onto the burner hearth at a relatively low temperature and thenintroducing the oil to a predetermined position onto the hearth which,during the normal operation of the burner, will have a temperatureconsiderably greater than the end,

point of oil, and mixing air with the oil so delivered in suchquantities so as to cause complete combustion of the hydrocarbon andcause the flame to burn in suspension above the outer peripheral rim ofthe burner hearth.

Other important objects of the invention are the provision of a new andimproved oil burner having a vaporizing area which, during the normaloperating cycle of the burner, is brought to temperatures not less thanthe end point of the fuel used; which has an air supply directly overthe vaporizing area so as to eliminate pockets or cold spots; whichdirects the oil into the vaporizing zone and completely surrounds itwith air; which is provided with means so that the flame will burn insuspension in any size of setting; which is so constructed and. arrangedto insure the proper control and velocity and direction of the incomingair; and which insures the talging place of combustion in the presenceof high heat reflecting media.

Numerous other objects and advantages will apparent throughout theprogress of the following specification.

The accompanying drawing illustrates a selected embodiment of theinvention and the views therein are as follows:

Fig. 1 is a detail vertical sectional view of one form of the improvedburner.

Figs. 2, 3 and 4 are detail vertical sectional views of other forms ofburners embodying the same or similar principles.

Referring to the drawing, each burner therein shown is provided with aunit (not shown) but which consists of a motor, blower housing, electricvalve, float valve, burner frame, and other mechanism of the usualconstruction, all of which serve to bring a regulated amount of fuel andair in the proper proportion as desired to the combustion chamber. Theabove unit is an essential part of the burner and may be any con;-ventional unit just so draft is supplied proportionally to the amount offuel consumed and the fuel delivered at a predetermined or definitepressure. Whether .the delivery of air and oil be accomplished by apower driven fan or by nat-' ural draft is not essential to theperformance of the combustion chambers of the burners.

The particular types of burners herein shown for the purpose ofexplaining the invention each comprise a bowl or burner body 5 to whicha draft tube 6 is operatively connected. particularly at the lower endof the body as shown in the various figures. Each body 5 may haverelatively straight outer sidewalls 1 which may be in the form of acylinder to conform with the normal shape of the fire box of the. heateror furnace into which the burner is set or applied. The exterior walls 1of each burner, the bottom 8 and the flue 9, which is preferablycentrally disposed, may be made of cast metal and lined or covered withrefractory material in to provide a hearth H,

Each hearth H has a sloping or inclined portion I? which slopesdownwardly and outwardly from the central flue 9 so that theliquid,-hydrocarbon or oil passing through the feed line it will flowdirectly upon the sloped or inclined surface i2 and then drain, bygravity, into the depressed groove Hi. Each hearth is also provided withan upstanding peripheral edge I5 which is located exteriorly of thegroove l6 and extends a predetermined distance above the normal upperedge of the hearth A plurality of inwardly and radially extendingfingers or arms 116 are spaced about the inner periphery of theupstanding edge l5 and extend over the outer edge of the fuel groove Itas clearly shown in all the figures.

The fuel intake lines l3 are each disposed within or adjacent thecentral flue 9 and are each operatively connected to the line I! whichis housed in the draft tube 6 and which lead to a suitable. source ofliquid fuel supply. The flue 9 is in direct open communication with thedraft tube 6 and therefore the incoming draft will always keep the fuelsupply line at a relatively cool temperature and thereby prevent carbondeposits from occurring in the fuel line and at the outlet of the fuelline.

Each burner is also provided with a deflector l8 which may be arrangedimmediately above the flue 9 for the purpose of deflecting the air in apredetermined direction to cause the air to impinge against a portion ofthe hearth to cause proper mixing of the oil and air. thereby insuringcomplete combustion of the oil and causing the flame to burn insuspension.

From an examination of the drawing it is obvious that the fuel comingthrough the feed line will pass up through the feed lines and dischargefrom the ends of the feed lines and flow, as well as be blown by theair, outwardly along the sloping surface of the hearth and into thegroove where it will become vaporized by the heat of combustion andmixed with the airv The arrows on the various drawings indicate the pathof the air, the air striking a part of the hearth, turning a portion ofthe air downwardly and causing a rapid rotation with the fuel producingan intimate mixture which rises upwardly and [burns on top of the hearthat the outer peripheral edge thereof.

The burner construction shown in Fig. 2 is suitable or applicable to thelarger types of burners and the air employed is delivered around theouter edge of the hearth to assist in supporting combustion on top ofthe hearth. In this later adaptation the fuel line I3 is provided with aplurality of fuel outlets I 9 which deposit the fuel onto the part ofthe hearth inwardly of the groove where it flows, by gravity, into thegroove and is vaporized as previously mentioned. The outer walls 5 ofthe burner shown in Fig. 2 are spaced from a jacket 20 to provide an airpasage 2| communicating with the main air stream coming through thedraft tube 6. A straight ledge 22 projects outwardly from the upper edgeI5 of the hearth, and this ledge is provided with a plurality of spacedopenings 23 through which the air in the passage 2| will pass to mixwith the vaporized combustible fuel and assist in spreading the flameand burn in suspension.

In Fig. 3 the deflector i8 is made in two parts to provide a central airpassage 24 which will cause the air to impinge against an inner sideedge of the hearth, part of the air being deflected downwardly and thenupwardly as denoted by the arrows in that figure.

In Fig. 4 the air is so directed that it first strikes the verticalportion 25 of the hearth where it will divide, part of it turning down.into the oil groove causing a rapid revolving gaseous mixture which willburn on top of the lining of the hearth as indicated at 26.

The principles involved in this invention deal with various grades offuel 011 each of which may have a definite flash point, Distillationtests show point of fuel oil is usually between 550 degrees Fahrenheitand 600 degrees Fahrenheit. The process herein employed is characterizedby the fact that the hearth be maintained at temperatures at least equalto those necessary to produce complete vaporization of the fuel burned.It has been found that if the air is not properly directed and thehearth properly shaped, the fuel will burn directly against the hearthand cause dirty, sooty combustion with considerable noise as well ascause carbon deposits. However, as in the present invention where theair has been directed in a particular manner and the shape of the hearthis of the kind herein shown. the flame will be lifted off the hearth andburn in suspension, causing highly efficient combustion, eliminatingnoise to a minimum. and leave the hearth clean without any trace ofcarbon. This latter accomplishment is caused by the shape andconstruction of the various distributing heads and by the shape andconstruction of the hearth.

The construction, herein shown, for the purpose of illustration only,show various burners having the entire vaporizing area supplied with adraft of air so as to eliminate carbon formation on the supply tubes aswell as subjecting the entire hearth to the reflected heat of the flameand keep the hearth at a relatively high temperature.

In conventional oil burners the temperature of the vaporizing area isexceedingly low. This is particularly true around the point of oilentrance where the feed pipe is fastened directly into the lower portionof the pot. In some cases it has been found that the temperature will beas low as 250 degrees Fahrenheit with the end point of oil used beingaround 600 degrees. It is apparent, therefore, that a carbon formationof residual content will build up around these points. It is this lowtemperature which results in clogging the feed line of the conventionalpot type burner. In some designs where higher temperatures exist, it wasnoted that the clogging or carbon deposit occurred inside of the end ofthe feed pipe due to the pipe becoming heated andthe oil vaporizinginside of the pipe without adequate air supply to completely burn theresidue. It is, therefore, one of the preferred embodiments of thisinvention that the oil be projected or flowed onto the vaporizing areain such a manner that the feed pipe will remain cool whereas thevaporizing area will remain hot.

By locating the feed line itself in direct communication or in closecontact with the main air stream, the feed line will be kept relativelycool, and the oil depositing onto the hearth, by gravity, or by beingblown by the air passing around-it, there will be no contact whateverbetween the oil feed line and the vaporizing area. The presentinvention, therefore, provides a construction in which there will not beany stoppage or clogging of the fuel line because of the principleherein set forth.

Temperature tests performed on devices embodying the principles of thisinvention and as exemplified broadly in Fig. 1, show that during certainperiods of operation, temperatures as high as 1100 degrees Fahrenheitwill be maintained in the vaporizing area, while the feed pipe will onlybe slightly warmer than that of the incoming oil.

Attempts to establish similarly high temperatures in the vaporizing areaof conventional pot burners resulted in the cracking of the oil as wellas the leaving of carbon deposits. The oil cracking and carbon depositsoccurring in pot burners were caused by insufficient air in thevaporizing area and because of the fact that the flame was not entirelyin suspension. This condition was also enhanced by the fact that theside walls of the combustion chamber remained relatively cool.

The usual pot types of burners which usually employ the primary andsecondary air principle, depend upon a relatively low temperature and alimited amount of air in the lower portion of the bowl for the operationof that type of burner results in a common weakness due to the lowtemperatures at which residual formation occurs around the feedentrance. The characteristics of the present invention and theemployment of the process herein described calls fora relatively hightemperature on the hearth suflicient to completely consume the residualcontent of the oil as-well as vaporize it completely through the endpoint.

The present invention provides for clean com bustion, completecombustion of the oil and for the burning of the flame in suspensionabout the peripheral edge of the burner similar to the rotary type ofoil burner' without the employment of the expensive and intricateconstruction of the rotary type. The present invention produces burnerswhich are highly eflicient and carbon free and which put intopractice'the following principles which have been found to be essentialand better by having the vaporizing area of the hearth maintained at atemperature not less than the end point of the oil used. The inventionalso supplies air and directs it over the entire vaporization area insuch a manner as to eliminate pockets and cold spots as well asdirecting the oil into the vaporizing zone completely surrounded by air.The combustion takes place in the presence of a high heat reflectingmedium and the resultant flame burns in suspension in any size andsetting.

The burners herein shown and others constructed in accordance with thepresent teachings, may operate on the high-low" principle where a smallfire is maintained during the socalled off-periods, and a high or largeflame is maintained during the normal operating periods.

The invention is capable of being operated by a gas pilot by placing thepilot in such a manner as to .cause proper ignition. Or, electricignition may be employed by the introduction of a jump spark or aheating element in the oil groove, or at some other point bestdeterminecl to cause proper ignition.

When burners constructed in accordance with the present invention areoperating on the highlow principle, and inthe event of flame failure,provision may be made to take care of the collected oil which willaccumulate over the hearth. Means for taking care of the excess oil soaccumulated may constitute a return line provided at some point in thehearth, or the accumulated oil may be allowed to flow through thecentral flue where it will flow to the bottom of the draft tube 30, Fig.1, where it can be led into a trip bucket of some kind to shut off themachine upon the accumulation of a definite weight of oil.

The device, as herein shown, may also be constructed with a low oil headon the feed line by using a low point of entrance to the hearth so thatthe accumulation of oil will not be suflicient to cause overflow in thecase of flame failure. When operating intermittently, this latterfeature may be handled by controls which shut down the burner after apredetermined period of operation without establishing fire.

The invention provides a highly eflicient burner which can be veryeconomically manufactured and causes a hot flame to burn in suspension.Furthermore, all danger or possibility of the clogging of the fuel linehas been positively eliminated.

Changes may be made in the form, construction, and arrangement of theparts without departing from the spirit of the invention or sacrificingany of its advantages, and the right is hereby reserved to make all suchchanges as fairly fall within the scope of the following claims.

The invention is hereby claimed as follows:

1. An oil burner comprising an upwardly extending receptacle open at thetop, a hearth arranged in the receptacle, said hearth having anoutwardly and downwardly sloping surface and an annular groove formed ina lower outer portion thereof and a wall above and outside of saidgroove, a fuel feed line arranged to convey fuel to said burner and todischarge fuel upon the sloping surface whereby oil gravitates to thegroove, an air supply line leading to the interior of said receptaclesubstantially centrally thereof, and means cooperating with the airsupply line and positioned to discharge air radially from said supplyline above the surface of the fuel feed line and against said wall,whereby said air is divided into an upward and a downward stream.

2. A burner comprising a hearth having an air opening, an outwardly anddownwardly sloping upper surface terminating in an oil retaining andvaporizing groove adjacent its outer edge and an upstanding marginalwall having an inwardly projecting portion overlying a material portionof said groove, means for flowing oil onto said sloping surface nearsaid air opening, and an air distributor cooperating with said airopening and positioned to directly impinge a flat stream of air againstthe inner surface of said projecting portion so that said stream willdivide into upwardly and downwardly directed streams.

3. A burner comprising a stationary hearth having an air opening, anoutwardly and downwardly sloping upper surface on the hearth terminatingin an oil retaining and vaporizing groove adjacent its outer edge and anupstanding marginal wall having an inwardly projecting portion overlyinga portion of said groove, means for flowing oil onto the slopingsurface, and an air distributor co-operating with the air opening andpositioned to impinge a stream of air against the inner surface of theprojecting portion so that the stream will be deflected downwardly andupwardly.

OSCAR L. BOCK.

